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Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Customer has an older 20 ton self contained R-22 rooftop

Customer Question

Customer has an older 20 ton self contained R-22 rooftop A/C. What is the factory charge for this unit ?
JA: You just pay a $5 deposit now and the rest only when you get a reply from the HVAC Technician. All of this is 100% satisfaction guaranteed, so you can get a refund if you're not happy for any reason.
Customer: OK
JA: Did you double-check the thermostat? And what about the unit's filters?
Customer: What is the factory charge of R-22 ?
JA: Do you plan on doing the work yourself?
Customer: YES I am a HVAC TECH
JA: Anything else we should know to help you best?
Customer: I need to know the weighed in charge of R-22 for this system.
Submitted: 1 month ago.
Category: HVAC
Expert:  Sean replied 1 month ago.
Good evening , I look forward to helping you.....Do you have the model number of the unit
Customer: replied 1 month ago.
This unit does not have any unit information tag. It is approximately 40 yeats old and is a semi hermetic unit self contained system rated at 20 tons.
Expert:  Sean replied 1 month ago.

I won't be able to guess the system size without that. I would just charge by superheat or subcooling until proper charge is achieved

Customer: replied 1 month ago.
Just tell me the factory weighed in charge please.
Customer: replied 1 month ago.
IT IS A SELF CONTAINED SYSTEM AND WOULD HAVE A RECOMMENDED FACTORY R-22 AMOUNT
Customer: replied 1 month ago.
IT HAS BEEN MY EXPERIENCE THAT IT IS SAFER TO GO WITH A FACTORY CHARGE
Expert:  Sean replied 1 month ago.

Im going to opt out and see if another expert can help

I understand your question but it could be 10lbs or it could be 50lbs I can't tell you exactly with out a model number, my recommendation and what I would do In the field is charge by superheat or subcooling

Customer: replied 1 month ago.
IT IS TO EASY TO OVERCHARGE A SEMI HERMETIC BY TEMP/ PRESSURE
Customer: replied 1 month ago.
A YORK 3 PHASE SEMI HERMETIC 20 TON SELF CONTAINED R-22CONDENSING UNIT EVEN WITHOUT A MODEL NUMBER SHOULD HAVE A STANDARDIZED REFRIGERANT CHARGE.
Customer: replied 1 month ago.
THIS UNIT IS APPROXIMATELY 40 YEARS OLD.
Expert:  airheatman replied 1 month ago.

Previous expert is correct that we would need a model number to look up the factory charge.To ask without the model is like asking what spark plug a 40 year old Chevy would use without knowing what engine was in it.Do you have any info at all that may lead us in the direction to find charge? Is it a single or dual circuit?

As a rule of thumb about 20lbs of refrigerant for each circuit in a 20 ton 2 circuit system would be normal

Expert:  airheatman replied 1 month ago.

Here is an example with a single circuit where charge shows 29.6 lbs, So as you can see the model is going to be of utmost importance

Expert:  airheatman replied 1 month ago.

So if we use the old standard 20 lbs per 10 ton circuit we would be way overcharged

Customer: replied 1 month ago.
TALK WITH A YORK ENGINEER AND GET BACK TO ME. IT IS A SINGLE SEMI HERMETIC COMPRSSOR IN A SELF CONTAINED ROOF TOP SYSTEM...........I WILL PAY ADDITIONAL AMOUNT WHEN I GET A CORRECT ANSWER
GO BACK 40 YEARS................HOW MANYDIFFERENT YORK SELF CONTAINED 20 TON ROOFTOP UNITS COULD HAVE BEEN MADE THEN; AND WOULD'NT THEY RECEIVE A STANDARDIZED CHARGE.
Expert:  airheatman replied 1 month ago.

Will do.My local York Dealer is M&S Supply.I will give him a call tomorrow and see if he can help us

Customer: replied 1 month ago.
OK.................................THANK YOU
Expert:  airheatman replied 1 month ago.

As you can see below there are just a bunch of different York packaged units.(and this is just some of them)Maybe the age will help us narrow it down.Will let you know.

Expert:  airheatman replied 1 month ago.

Called York this morning .As far back as they can pull up specs is 1995. Those units total charge was 37.6 lbs